This invention relates to the field of integrated circuits. More particularly, this invention relates to communication between different voltage domains within an integrated circuit.
It is known to provide integrated circuits operating with multiple voltage domains. For example, one voltage domain may be designed for low power operation, such as for a real time clock. Such a domain may use an unregulated power supply and thick gate oxide transistors. A further voltage domain within that integrated circuit may be targeted at low dynamic power and accordingly use a lower regulated voltage, such as to support a processor core. A difficulty arises in communicating signals between these voltage domains as the voltage difference increases and the demands for ever lower power consumption also increase.